Devices with rotating blades such as concrete cutting saws include a blade mount or arbor received in the arbor hole of the blade. U.S. Pat. No. 5,603,310, incorporated herein by this reference, discloses a three-sided arbor and a corresponding blade arbor hole configured the same as the arbor. U.S. Pat. No. 6,651,644, also incorporated herein by this reference, discloses a blade arbor hole with a “cut gem” configuration designed to be attached to different types of arbor.
The applicant's prior blades had an arbor hole configured as a square with one corner cut-off. The arbor hole has four fairly long sides and one fairly short angled side. This design worked well for saws with a traditional three-sided arbor.
Recently, however, at least one saw manufacturer has changed the configuration of the three-sided arbor so that the applicant's blades cannot be properly secured to the arbor. Moreover, due to various patents covering different blade arbor hole configurations, users of saws have limited choices in selecting after market saw blades.